Radiation causes cellular degradation due to damage to DNA and other key molecular structures within the cells in various tissues. It was discovered that with controlled amounts of radiation, the effects caused by radiation can be utilized to treat certain diseases. With the use of radiation, several previously untreatable diseases have been able to be successfully treated using radiation therapies. However, along with the curative effects of radiation are negative side effects. The prolonged exposure to radiation include both immediate and delayed side effects. The immediate side effects of radiation exposure include nausea and vomiting, headaches, fevers, and skin burns, whereas the delayed effects could include fatigue, weakness, hemorrhaging, leukopenia, epilation and other various side effects. Additionally, the prolonged overexposure of unnecessary radiation may cause more serious complications and may lead to mortality. Due to the serious side effects of utilizing radiation as a form of medical treatment, numerous steps have been taken to limit the exposure of radiation to healthy tissue by focusing the radiation solely on the diseased tissue.
External beam radiation therapy, the most common form of radiation therapy, is the application of radiation at a particular part of the body with the use of an external source of radiation. External beam radiation therapy directs concentrated radiation to the treatment area from outside of the body. To minimize the exposure of the concentrated radiation to healthy tissue, the concentrated radiation beam is precisely controlled by the use of mechanical hardware and computer software. Current technology allows radiation to be precisely focused on the diseased tissue occupying a minuscule area on a larger healthy tissue. The use of multiple low-radiation beams focusing on an area of diseased tissue at different approach angles creates a single, focused and concentrated radiation beam. This exposes the surrounding healthy tissue to lower levels of radiation due to the use of multiple low-radiation beams. The advancements in technology have allowed the precise delivery of the concentrated beams to a diseased tissue while minimizing the exposure to the surrounding healthy tissue.
The course of radiation treatment typically consists of multiple daily treatments (20 to 40) over a course of 4 to 8 weeks, and each day the radiation treatment is given over a period of about 15-30 minutes. Although the directed radiation beam precisely delivers the radiation to diseased tissue, its frame of reference is to a stationary patient and traditionally does not take into account the natural and unnatural movements of a patient during that 15-30 minute treatment. In more advanced techniques where higher levels of radiation are used, in order to allow the patients to fully benefit from the procedure and minimize its side effects, the delivery of the radiation must be precise, requiring radiation alignment accuracies in range of millimeter. Due to the fact that the radiation dose is delivered over a period of 15-30 minutes during which patient must remain still. The slight movement of a patient during a treatment will alter the point of delivery of the concentrated radiation beam, therefore reducing the exposure of radiation to the diseased tissue while increasing the exposure of radiation to the healthy tissue. The treatments then become less effective which would require additional treatment, further exposing the surrounding healthy tissue to unneeded radiation or other treatment types. The patient's movements must be eliminated or minimized to ensure proper delivery of radiation to diseased tissue and minimize the exposure to healthy tissue.
Currently, there are two major ways to monitor movement of the patients. One is a technician must constantly watch the patient via a in-room video to make sure they are not moving for up to a 30 minute period. This is error prone since it is subject to the technician interpretation of movement.
In order to minimize the movements, patients are traditionally subject to invasive and uncomfortable methods of immobilization. Methods include utilizing stabilizing frames attached to the body, stabilizing body casts or plastic molds, and internal spacers inserted within a patient's body to stabilize the diseased tissue. To control the tolerance of a patient's movement, tight clearance is required. This may cause discomfort and pain as the patient is tightly held in a single position for periods of up to 30 minutes for a single treatment. The physical restriction of the movements of the patient may cause or increase the levels of anxiety, resulting in heavier and quicker breathing. This is particularly important when treating diseased tissue that moves with any bodily function associated with breathing or involuntary cough. For children with cancer that require radiation treatment and cannot cooperate to remain still, they require daily general anesthesia, where they have to be put to sleep with invasive sedative medications via an intravenous route and require oxygen through their nose and mouth. This daily procedure typically costs an additional $5,000 to 6,000 per day, requires additional medical staff (such as anesthesiologists and nurses), medical equipment, and results in a longer treatment time. Besides being invasive, treatment involving general anesthesia requires an additional 3-5 hours per day for these young patients due to induction and recovery time.
Patients generally prefer to be unrestrained. In instances where the use of mechanical stabilization devices is undesirable or not feasible, the patient must refrain from moving, including the momentary cessation of breathing. To ensure the patient has not moved from their initial position and ensure proper alignment of the radiation with the diseased tissue, a technician must continually monitor the movements of the patient. The technician may be error prone as it requires the technician's interpretation of whether the patient has moved a distance as little as few centimeters. Alternatively, the precise monitoring of a patient's bodily movement can be monitored using real-time 3-dimensional surface imaging techniques. Using real-time 3-dimensional surface imaging techniques, the patient's current body position is continually cross-referenced with an ideal reference image, which is used to calculate the coordinates to deliver radiation. If movement is detected the technician is alerted and the technician alerts the patient not to move, eliminating the need for a technician's judgment of a patient's body position.
The current standard way to monitor movement of the patients requires a technician to constantly watch the patient via an in-room video to make sure they are not moving for up to a 30 minute period. This is error prone since it is subject to the technician interpretation of movement; it only shows only gross movement or body positioning. This system does not allow patient's participation and monitoring of his/her movement, and patients has no control or awareness. If the technician sees body movement, he/she has to re-enter to treatment room to re-adjust patient position to match the reference position, and this adds additional time to the treatment.
One system (the Varian® Real-time Position Management™ or RPM), a currently existing medical device (VisionRT), uses real-time 3-D surface imaging incorporating an in-room camera to monitor movement. This monitoring is achieved by comparing the live three dimensional patient surface images with reference images and the system provides the difference between the 2 image sets to the technician. When movement is detected and the workstation will alert the technician, the technician alerts the patient not to move. There is some delay (deadtime) between time the movement is detected and the technician instruction to patient. This approach is even less effective when patients are experiencing pain and uncontrolled movements, as well as those with hearing impairment or are simply too young to understand the technician's instructions.
The control of radiation exposure is particularly challenging for children because children are naturally more anxious than adults. Staying still for prolonged periods of times for the treatment is a difficult proposition for children and the use of mechanical stabilization devices or sedatives is commonly used. The mechanical stabilization devices generally cause additional anxiety in children as they are bound and immobilized, resulting in crying, screaming, and minute movements as they struggle to become free. The use of sedatives, although effective to immobilize, comes with medical risk of the sedative medications, costs (up to several thousands dollars per treatment), and extended induction and recovery time (3-5 hours per treatment). This risk is repeated every day, 5 days per week, for period of 3-6 weeks.
In light of the above, it would be advantageous to provide an apparatus and method to decrease the movement of patients undergoing radiotherapy. It would further be advantageous to provide an apparatus and method to decrease the movement of patients undergoing radiotherapy which does not use physical restraints or chemical sedatives to immobilize a patient. It would further be advantageous to provide an apparatus and method to decrease the movement of patients undergoing radiotherapy which is non-invasive and comfortable. It would further be advantageous to provide an apparatus and method to decrease the movement of patients undergoing radiotherapy which monitors the real-time position of a patient and relays the information to the patient about the specific area of the body and allows patient to make adjustment to get back to the reference or desired position. It would further be advantageous to provide an apparatus and method to decrease the movement of patients undergoing radiotherapy which alerts a third party (operator or technician) of excessive movement outside a set range and which part of the body. It would further be advantageous to provide an apparatus and method to assure the safely to patients undergoing radiotherapy which send an interrupt signal instantly to the radiation equipment to pause the radiation beam due to excessive movement outside a set range. It would further be advantageous to provide an apparatus and method to decrease the movement of patients undergoing radiotherapy which provides a virtual reality system which visualizes the patient's current physical and biometric measurements and allows for the real-time adjustment of their physical and biometric measurements in response.